Relay



J. ERICKSON.

RELAY.

APPLICATION FILED DEC-8,1917,

Patented Feb. l), 1930.

fnverzzazf- Jahn Erickson ZYUPnEy.

UNITED STATES PATENT OFFICE.

JOHN ERICKSON, OF CHICAGO, ILLINOIS, ASSIGNOR TO AUTOMATIC ELECTRICCOMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

array.

Specification of Letters Patent.

Patented Feb. 3, 1920.

Application filed December 8, 1917. Serial No. 208,818.

To all whom it may concern:

Be it known that I, JOHN ERIGKSON, a citizen of the United States ofAmerica, and a resident of Chicago, county of Cook, and State ofIllinois, have invented certain new and useful Improvements in Relays,of which the following is a specification.

My invention relates to electromagnetic circuit closing devices, andmore specifically to a relay for closing any kind of a circuit.

One of the objects of my invention is to provide a relay which may beconnected 1n circuit with sources of either alternating or directcurrent and which may be arranged to operate with the direct currentonly or with alternating current only, or which may operate in aparticular manner with both alternating current and direct current.

Another object of my invention is to provide a relay which utilizes the\Vheatstone bridge principle as applied to magnetic flux rather than toelectric current and in which the armature of said relay forms thebridge across the arms of a VVheatstone bridge corresponding to thereceiver or galvanometer bridge.

Another object of my invention is to provide a relay which may beconnected in circuit with a direct current and which will attract itsarmature momentarily when the circuit is closed and again onlymomentarily when the circuit is broken.

My invention is adapted for various uses such as in a telephone systemin which a relay is desired which will not operate with ringing currentbut which will operate with direct or operating current. Also in powerwork such a device may be used to great advantage.

Other features and objects of my invention will be pointed out in thespecification by referring to the accompanying drawings in which Figure1 shows one form of my improved.

rela a Fig. 2 is an end view of the relay shown in Fig. 1 taken from theleft of said figure. Fig. 3 is a top view of the relay in Fig. 1. Fig. 4shows another form of my improved relay, and Figs. 5 and 6 are,respectively, an end view and a top view of the relay shown in Fig. 4

I will now describe my invention more in detall. Referring to Figs. 1, 2and 3, I have shown a coil 2 mounted upon an iron mountmg bracket 3 atone end by means of the screw 5, and having another iron pole piece 4firmly secured to the other end thereof by means of the screw 6. Thecoil 2 has a pair of terminals 7 and 8 to which any desired circuit maybe connected. Firmly mounted between the upper extending ends of thebrackets 3 and 4 are a pair of parallel soft iron cores or rods 9 and10, which are secured by iron screws to the two brackets 3 and 4. On theright hand end of the core 9 is firmly attached a copper slug 11 and onthe left hand end of the core 10 is secured another copper slu 12. Thesetwo copper slugs are mounted ar enough apart to leave space for thearmature 13 which is pivoted at the points 14 and 15 and held normallyaway from the cores 9 and 10 by means of the coil spring 16, therebymaintaining a pair of springs 17 and 18 normally out of contact. Atcertain times to be pointed out hereinafter, the pole pieces 9 and 10will be charged as opposite pole pieces and will therefore attract thearmature 13 to close the contact of springs 17 and 18.

The relay which I have described and which is shown in Figs. 1, 2 anddis designed so that the armature 13 will be attracted only whenalternatin current is flowing through the coil 2. A so the armature 13will be attracted momentarily whenever a direct current is applied tothe coil 2, and will again be momentarily attracted when the directcurrent is removed from the circuit of said coil. It will be seen thatthe path of the magnetic flux caused by apply- 111 a direct current tothe winding of the C011 2 includes the core of said coil, the

bracket 3, the cores 9 and 10 in multi le, the heel piece 4, and back tothe core of ooil 2. As is well known in the art, the cop er slugs 11 and12 have a retarding action w ich acts against any change in the magneticflux fiowin in their respective cores 9 and 10 so that w en a ma ieticflux is set up around the above traoed circuit its increase or decreasein stren th will be opposed at two places, that is, t e flax in theright hand end of the core 9 will be opposed by the counter force set upin the slug 11, and the magnetic flux in the core 10 will be opposed 1nthe left hand end of said core by the counter action of the slu 12. Thusit will be seen that the mid points of the cores 9 and 10 will actas'north and south magnetic poles and cause the armature 13 to beattracted to said mid points, thereby short circuiting magnetically thetwo slugs 11 and 12. The magnetic flux will-now ow from the core of coil2, bracket 3, coil 10, to the mid point thereof, armature 13, and onthrou h the left hand half of core 9, and throng pole piece 4 to thecore of coil 2. As soon, however, as the magnetic flux in the two cores9 and 10 has reachedits maximum point and the counter force generated inthe slugs 11 and 12 dies down, the cores 9 and 10 will form a free pathto the flux and the armature 13 will fall back. In the same manner whenthe direct current circuit through the (-oil 2 is opened the slugs 11and 12 will again oppose the decrease in flux in the two cores 9 and 10and the armature 13 will again be momentarily attracted by the countermagnetic force generated therein. It will be seen that I have utilizedthe VVheatstone bridge principle as applied to flux rather than electriccurrent and that the coil 2 and its core act as the battery bridge,

the left hand end of the core 10 and the right hand end of the core 9act as the variable arms and the right hand end of the core 10 and theleft hand end of the core 9 act as the fixed arms of said bridge, whilethe armature 13 acts as the receiver or galvanometer arm. Therefore whenthe two variable arms are changed in resistance relative to the fixedarms by the counteraction of the slugs, a pull is exerted on thearmature 13.

Now, when an alternating current is supplied to the winding of the coil2 it will be seen that, as the alternating current 1s continuallychanging in direction, the magnetic flux in the cores 9 and 10. willnever be steady and therefore the counter force in each slug 11 and 12which is caused by a change in the flux of the cores 9 and 10, will bemaintained constant and the armature 13 will therefore be held in itsattracted position.

In Figs. 4, 5 and 6 I have shown another form of my improved relay whichacts in a much different manner. This relay is designed to be slow toenergize when direct current is applied thereto and quick to deenergizewhen the direct current is removed.

Also this relay is not responsive to alter nating current. In Figs. 4, 5and 6 I have shown a relay which is very similar to the relay shown in.Figs. 1, 2 and 3, except that its armature is pivoted in a differentmanher so as to rcspond to direct current. In

these figures a. coil 19 is shown mounted on a heel piece 20. Firmlysecured to the upper end of this heel piece are a pair of parallel cores22 and 23 which correspond to cores 9 and 10 of Fig. 1 and Which haveslugs and 25 mounted thereon. On the opposite'end of the cores 22 and 23is loosely mounted or hinged, an armature 21 having a tail piece 27which extends back to the mid point of the cores 22 and 23 and isnormally held against said cores by the spring 29, which, therefore,also holds the armature 21 away from the core of the coil 19. This relaywill operate in the following manner. When direct current is applied tothe coil 19 a flux will be generated which follows a path from the coreof coil 19 through heel piece 20, cores 22 and 23 in parallel, throughthe armature 21 and back to the core of said coil. The armature 21 willnot be attracted at once, however, due to the pull which is exerted onthe tail piece 27, which is held against the cores 22 and 23 until thecounter action of the slugs 24 and 25 is overcome, in the same manner inwhich the armature 13, Fig. 1, was attracted, at which time the forceexerted on the tail piece 27 will die out and the armature 21 will pullup and close the contact of springs 28 and 29 to close any desiredcircuit. Now when an alternating current is applied to the terminals ofthe coil 19, the tall piece 27 will be held permanently against thecores 22 and 23 in the same manner as was the armature 13 in Fig. 1, sothat the armature 21 will not have a chance to pull up.

Therefore it will be seen that I have deyised a very efficient and novelrelay which is adapted for many uses and which may be arranged to closean alarm circuit or signal circuit momentarily when a .direct currentcircuit is closed and again When it is opened and which will not hold upon direct current. Also it may be used when it is desired to have arelay which will be slow to energize with direct current and which willnot energize with alternating current.

Haying fully described my invention what I desire to protect and secureby Letters Patent will be pointed out in the appended claims.

What I claim as my invention is:

1. In a relay, a magnet, an armature for said magnet, means for applyingdirect and alternatmg current to said magnet, means for preventing saidarmature from being attracted when alternating current is applied tosaid magnet, means for causing said armature to be slow in pulling upwhen direct current is applied to sald magnet and means for causing saidarmature to fall back quickly when said direct current is removed.

2. In a relay, a magnet, an armature for said magnet pivoted at onepoint and having two arms extending therefrom at right angles to eachother, means for applying currents of different characters to saidmagnet, means for attracting said armature in one direction when currentof one character is applied and in the other direction when currentofranother character is applied to said magnet.

3, In a relay, a magnet, an armature for said magnet pivoted at onepoint and having two arms extending in two directions therefrom, meansfor applying alternating and direct current to said magnet, means forattracting one of said arms when alternating current is applied to saidmagnet and for attracting the other of said arms when direct current isapplied to said magnet.

4. In a relay, a magnet, an armature for said magnet, means for applyingdirect and alternating current to said magnet, means for preventing saidarmature from being attracted when alternating current is applied tosaid magnet, means for causing said armature to be slow in pulling upwhen direct current is applied to said magnet, means for causing saidarmature to fall back quickly when said direct current is removed, and acircuit controlled by said relay.

5. In a relay, a magnet, an armature for said magnet pivoted at onepointand having two arms extending therefrom at right angles to each other,means for applying currents .of different characters to said magnet,means for attracting said armature in one direction when current of onecharacter is applied and in the other direction when current of anothercharacter is applied to said magnet, and a circuit controlled by saidrelay.

6. In a relay, a magnet, an armature for said magnet pivoted at onepoint having two arms extending in two directions therefrom, means forap lying alternatin and direct current to ear magnet, means orattracting one of said arms when alternating current is applied to saidmagnet and for attracting the other of said arms when direct current isapplied to said magnet, and a circuit controlled by said relay.

7. In a relay, said magnet pivoted at one point and having two armsextending therefrom at right angles to each other, means for a lyingcurrents of different characters tOSaI magnot, means for attracting saidarmature in one direction when current of one character is applied andin the other direction when current of another character is applied tosaid magnet, and a circuit controlled by only one of said operations.

8. In a relay, a magnet, an armature for said magnet pivoted at onepointhaving a magnet, an armature for two arms extending in two directionstherefrom, means for applying alternating and direct current to saidmagnet, means for attracting one of said arms when alternating currentis applied to said magnet and for attracting the other of said arms whendirect current is ap lied to said magnet, and a circuit controlle byonly one of said operations'.

9. In a relay, a magnet, a magnetic circuit for said magnet havingparallel branches, an armature for said magnet bridged across saidparallel branches, said branches at times short circuitin said armaturemagnetically, and means or removing said short circuit to cause saidarmature to be attracted.

10. In a relay, a magnet, a magnetic circuit for said magnet, saidmagnetic circuit comprising a Wheatstone bridge having a pair ofpermanent arms and a pair of variable arms, an armature for said magnet,said armature bridged across the points between the variable andpermanent arms, means for causing a magnetic flux to flow in saidcircuit, means for varying the reluctance of said variable arms, tocause the magnetic flux to flow through said armature and attract thesame.

11. In a relay, a magnet, a magnetic circuit for said magnet, saidmagnetic circuit comprising a Wheatstone bridge having a pair ofpermanent arms and a pair of variable arms, an armature for said magnet,said armature bridged across the points between the variable andpermanent arms, means for causing a magnetic flux to flow in saidcircuit, means for varying the reluctance of said variable arms to causethe magnetic flux to flow through said armature and attract the same,and a circuit cons trolled by said armature.

12. An electromagnet having a magnetic circuit, a portion of saidmagnetic circuit comprising a \Vheatstone bridge having two arms whichare of lowreluctance to magnetic flux generated by alternating current,and two arms which are of high reluctance to flux generated byalternating current, said arms having equal reluctance to flux generatedby a continuous flow of direct current, an armature for said magnethaving two points of said bridge as its pole pieces, whereby when analternating flux passes through said bridgeysaid pole pieces will becharged as opposite poles and attract said armature.

13. An clectromagnet having a magnetic circuit, a portion of saidmagnetic circuit comprising a lVheatstone bridge having two arms whichare of low reluctance to a magnetic flux generated by alternatingcurrent, and two arms which are of liignreluctance to flux generated byalternating current,

equal reluctance generated by a continuous flow of direct current, anarmature for said magnet,

having two points of said b 5 pieces, whereby when an passes throughsaid bridge,

will be charged as opposit ridge as its pole alternating flux said polepieces e poles and attract said armature, and whereby when a stead ordirect current flux passes through said ridge said armature will not beat- -10 tracted.

Signed by me at Chicago, Cook county, Illinois, this first day ofDecember, 1917.

JOHN ERIOKSON.

